Jim Flynn | bbfe603 | 2020-07-20 16:57:44 +0100 | [diff] [blame] | 1 | // |
| 2 | // Copyright © 2020 Arm Ltd and Contributors. All rights reserved. |
| 3 | // SPDX-License-Identifier: MIT |
| 4 | // |
| 5 | |
| 6 | #pragma once |
| 7 | |
| 8 | #include "Assert.hpp" |
| 9 | |
| 10 | #include <type_traits> |
| 11 | #include <limits> |
| 12 | |
| 13 | namespace arm |
| 14 | { |
| 15 | |
| 16 | namespace pipe |
| 17 | { |
| 18 | |
| 19 | #if !defined(NDEBUG) || defined(ARM_PIPE_NUMERIC_CAST_TESTABLE) |
| 20 | #define ENABLE_NUMERIC_CAST_CHECKS 1 |
| 21 | #else |
| 22 | #define ENABLE_NUMERIC_CAST_CHECKS 0 |
| 23 | #endif |
| 24 | |
| 25 | #if defined(ARM_PIPE_NUMERIC_CAST_TESTABLE) |
| 26 | # define ARM_PIPE_NUMERIC_CAST_CHECK(cond, msg) ConditionalThrow<std::bad_cast>(cond) |
| 27 | #else |
| 28 | # define ARM_PIPE_NUMERIC_CAST_CHECK(cond, msg) ARM_PIPE_ASSERT_MSG(cond, msg) |
| 29 | #endif |
| 30 | |
| 31 | template<typename Dest, typename Source> |
| 32 | typename std::enable_if_t< |
| 33 | std::is_unsigned<Source>::value && |
| 34 | std::is_unsigned<Dest>::value |
| 35 | , Dest> |
| 36 | numeric_cast(Source source) |
| 37 | { |
| 38 | #if ENABLE_NUMERIC_CAST_CHECKS |
| 39 | if (source > std::numeric_limits<Dest>::max()) |
| 40 | { |
| 41 | ARM_PIPE_NUMERIC_CAST_CHECK(false, "numeric_cast failed casting unsigned type to " |
| 42 | "narrower unsigned type. Overflow detected."); |
| 43 | } |
| 44 | #endif // ENABLE_NUMERIC_CAST_CHECKS |
| 45 | |
| 46 | return static_cast<Dest>(source); |
| 47 | } |
| 48 | |
| 49 | template<typename Dest, typename Source> |
| 50 | typename std::enable_if_t< |
| 51 | std::is_signed<Source>::value && |
| 52 | std::is_signed<Dest>::value |
| 53 | , Dest> |
| 54 | numeric_cast(Source source) |
| 55 | { |
| 56 | static_assert(!std::is_floating_point<Source>::value && !std::is_floating_point<Dest>::value, |
| 57 | "numeric_cast doesn't cast float."); |
| 58 | |
| 59 | #if ENABLE_NUMERIC_CAST_CHECKS |
| 60 | if (source > std::numeric_limits<Dest>::max()) |
| 61 | { |
| 62 | ARM_PIPE_NUMERIC_CAST_CHECK(false, "numeric_cast failed casting signed type to narrower signed type. " |
| 63 | "Overflow detected."); |
| 64 | } |
| 65 | |
| 66 | if (source < std::numeric_limits<Dest>::lowest()) |
| 67 | { |
| 68 | ARM_PIPE_NUMERIC_CAST_CHECK(false, "numeric_cast failed casting signed type to narrower signed type. " |
| 69 | "Underflow detected."); |
| 70 | } |
| 71 | #endif // ENABLE_NUMERIC_CAST_CHECKS |
| 72 | |
| 73 | return static_cast<Dest>(source); |
| 74 | } |
| 75 | |
| 76 | // numeric cast from unsigned to signed checked for narrowing overflows |
| 77 | template<typename Dest, typename Source> |
| 78 | typename std::enable_if_t< |
| 79 | std::is_signed<Dest>::value && |
| 80 | std::is_unsigned<Source>::value |
| 81 | , Dest> |
| 82 | numeric_cast(Source sValue) |
| 83 | { |
| 84 | static_assert(!std::is_floating_point<Dest>::value, "numeric_cast doesn't cast to float."); |
| 85 | |
| 86 | #if ENABLE_NUMERIC_CAST_CHECKS |
| 87 | if (sValue > static_cast< typename std::make_unsigned<Dest>::type >(std::numeric_limits<Dest>::max())) |
| 88 | { |
| 89 | ARM_PIPE_NUMERIC_CAST_CHECK(false, "numeric_cast failed casting unsigned type to signed type. " |
| 90 | "Overflow detected."); |
| 91 | } |
| 92 | #endif // ENABLE_NUMERIC_CAST_CHECKS |
| 93 | |
| 94 | return static_cast<Dest>(sValue); |
| 95 | } |
| 96 | |
| 97 | // numeric cast from signed to unsigned checked for underflows and narrowing overflows |
| 98 | template<typename Dest, typename Source> |
| 99 | typename std::enable_if_t< |
| 100 | std::is_unsigned<Dest>::value && |
| 101 | std::is_signed<Source>::value |
| 102 | , Dest> |
| 103 | numeric_cast(Source sValue) |
| 104 | { |
| 105 | static_assert(!std::is_floating_point<Source>::value && !std::is_floating_point<Dest>::value, |
| 106 | "numeric_cast doesn't cast floats."); |
| 107 | |
| 108 | #if ENABLE_NUMERIC_CAST_CHECKS |
| 109 | if (sValue < 0) |
| 110 | { |
| 111 | ARM_PIPE_NUMERIC_CAST_CHECK(false, "numeric_cast failed casting negative value to unsigned type. " |
| 112 | "Underflow detected."); |
| 113 | } |
| 114 | |
| 115 | if (static_cast< typename std::make_unsigned<Source>::type >(sValue) > std::numeric_limits<Dest>::max()) |
| 116 | { |
| 117 | ARM_PIPE_NUMERIC_CAST_CHECK(false, "numeric_cast failed casting signed type to unsigned type. " |
| 118 | "Overflow detected."); |
| 119 | } |
| 120 | |
| 121 | #endif // ENABLE_NUMERIC_CAST_CHECKS |
| 122 | return static_cast<Dest>(sValue); |
| 123 | } |
| 124 | |
| 125 | #undef ENABLE_NUMERIC_CAST_CHECKS |
| 126 | |
| 127 | } // namespace pipe |
| 128 | } // namespace arm |